Fountain pen



Sept. 13, 1955 w. KORESKA ET AL FOUNTAIN PEN Filed Aug. 26, 1952 INVENToRs WMM f1/@lla Afro/:usr

United States Patent O FOUNTAIN PEN Wilhelm Koreska and Robert Lausch, Vienna, Austria Application August 26, 1952, Serial No. 306,440

Claims priority, application Austria October 18, 1951 1 Claim. (Cl. 1Z0-42.16)

The present invention relates to antechamber type fountain pens. An antechamber type fountain pen is a fountain pen having in its casing two ink spaces of substantially different volume, which in normal use of the fountain pen are tightly sealed from each other. The smaller space, called antechamber, contains a quantity of ink gradually delivered to the nib in writing. The reservoir, which should be of substantial size, contains the supply of ink, from which the antechamber is filled from time to time, when the ink supply inthe antechamber is exhausted. This filling is effected by opening the antechamber valve to pass ink from the reservoir to the ink chamber.

The main idea underlying an antechamber type fountain pen consists in providing a fountain pen free from thermal blotting. Thermal blotting occurs in known fountain pens not designed on the antechamber principle. It is a result of the expansion of the air enclosed in the casing, more accurately speaking in its ink reservoir, under the influence of the warmth of the hand or of a reduction in atmospheric pressure. The latter influence causes, e. g., the leakage of fountain pens carried in an airplane. The antechamber type fountain pen avoids this drawback because the ink in the reservoir is hermetically sealed against the outside and does not permanently communicate with the nib. When the casing is warmed the enclosed air expands too and the pressure in the reservoir and the pressure gradient toward the outer air will increase but this will not cause leakage of ink. The chamber communicating with the nib, i. e., the antechamber, is too small to cause the leakage of an appreciable quantity of ink on a rise of temperature or drop of atmospheric pressure. This small size of the chamber requires means to enable it to be filled with ink quickly and simply.

Antechamber type fountain pens are not new per se. As far as is known, the first antechamber type fountain pen ready for commercial production and satisfactory in operation was described by Wilhelm Koreska among other patents in his German Patent No. 743,124.

Whereas the aforementioned earlier types of Koreskas fountain pen were very satisfactory as regards the quantity of ink stored, in conjunction with perfect freedom from blotting, they had the disadvantage that the casing had to be filled with a pipette or a small ink pump, i. e., by means of a separate implement which had to be available in addition to the ink supply bottle. Whereas an antechamber type fountain pen, owing toits greatly increased capacity, is filled much less frequently than a conventional pen filled, e. g., on the piston principle, the requirement of an auxiliary means for filling the said antechamber type fountain pens was considered a disadvantage.

It is an object of the invention to provide an antechamber type fountain pen which requires no separate implements for filling but can be filled merely by inserting the rear end of the casing into an ink supply container, e. g., a commercial ink bottle, whereupon the filling can be effected by a few simple manual operations.

2,717,578 Patented Sept. 13, 1955 It is another object of the invention to provide an antechamber type fountain pen in which the refilling of the antechamber, necessary from time to time, can be carried out more simply than before. Other objects 'and features of the invention will become apparent from the following description given with reference to the drawing.

ln this connection the reference to the front end of a pen designates the end of the casing where the nib is carried, whereas the rear end of the pen is the end of the casing remote of the nib. This terminology will be adhered to consistently hereinafter, for better understanding.

In the drawings,

Fig. 1 shows an embodiment of the fountain pen according to the invention;

Figs. 2-4 are enlarged sectional views taken on lines II--IL III-III and IV-IV, respectively, of Fig. 1; and

Fig. 5 is a view similar to that of Fig. 1, showing certain details.

In the embodiment of Fig. 1 there is shown the head part 2 carrying the nib 1 and an ink feeder 3 which frictionally fits in the head part. These details, which are not the subjected of the present invention, are explained more fully in the German Patent No. 743,124. The valve 4 comprises the guide extension 5, which is grooved in the manner known (see Fig. 2, grooves 6, 6') to enable the rapid filling of the antechamber 7 as soon as the valve 4 is lifted from its seats 8 by means to be described later. A sealing member (e. g., as rubber disk 10) carried by the valve body 4 within an annular groove of the same is pressed by the valve spring 11. The sealing ring 1i) provides a liquid-tight seal of the antechamber 7. For assembly reasons the separate part 13 provided with the valve seat 8 is formed between the part 2 and the outer rigid casing 14.

The riser tube 15 together with the valve body 4 is displaceable and this displacement can be effected from the rear without causing an escape of ink from the reservoir 16. The valve body 4 has in its extension 5 an ink passage 6 and opposite the same an air overflow passage 6. The internal cross section of the ink passage is smaller than that of the air passage (See Fig. 2). The difference in cross section facilitates the rapid exchange of air by ink when the antechamber 7 is being filled.

Moreover, the valve has a shoulder 19, on which bears the valve spring 11, which consists of a compression spring accommodated in the present example in the antechamber 7. The body 4 is slotted at 20. The slot receives a guide extension 21, which consists of a fixed lengthening piece of the ink feeder 3, and is inserted therein. The guide extension 21 could also be integral with the ink feeder 3 and elongate the same. Part 21 in conjunction with the guide slot 20 prevents a turning of the valve relative to the pen casing, to ensure that the overflow passages 6 and 6 always remain in the proper angular position relative to the nib 1. If the passage 6 were on the upper side during the filling of the antechamber 7, the filling operation would be interfered with considerably.

The valve 4 is connected with the riser tube 15 and guided by it. The tube 15 itself is slidable in a guide part 22 tightly fitting the container body 18. This guide part can be made of metal, plastics or the like. The front end of the tube 15 communicates under certain conditions, to be described later, through the passage 17 with the reservoir 16 while the other end of the tube 15 is normally closed by a rubber cap 23. In the end of the protective sleeve 14, which completely encloses the container 18 enclosing the reservoir room 16, a push button 24 is axially displaceable toward the nib 1 against the action of a spring 25. The spring 25 bears against a ring it l. 26, which is guided in the end portion of the sleeve 14, and in turn through another compression spring 27 bears on another ring 28, which can be displaced in the part 29 of the sleeve up to a snap ring 3i) after the sleeve 14 is screwed from the part 13. To this end a screw thread is provided on the parts 13 and 14.

Thus it can be seen that by pressure exercised on the button like part 24 toward the nib 1 the tube 15 is displaced together with the valve 4 toward the nib 1 and the springs 25, 27 and 11, and the cap 23 are compressed. The rear end of the tube 15 remains closed during its displacement. This displacement is sufficient to lift the valve 4 sufficiently from its seat in the part 13 so that the air in the antechamber 7 can flow through the passage 6 into the reservoir 16, and the ink contained in the latter can flow through the passage 6 into the antechamber 7, if the pen is held with the nib 1 pointing downwardly, a maneuver which can easily be fulfilled with one single hand by gripping the pen and pressing down the button 24 with the thumb. When the pressure on push button 24 is discontinued the valve 4 under the influence of the valve spring 11 will close to seal the antecharnber 7 against the reservoir 16.

Another feature of the invention resides in that the tube 15 is used as a riser tube also in refilling the reservoir 16. This filling is effected by exposing the rear end of the casing by unscrewing the sleeve 14 from the thread 31 and with it the rear end of the tube 15, which is now free and can now be dipped into an ink supply bottle.

To enable the pumping of ink from a supply container (not shown), which may consist of an ink bottle, into the reservoir 16, the air in that reservoir must be expelled and replaced by ink. Most simply this is performed by making the container 18 of moderately elastically deformable material, such as a suitable synthetic plastic. The deformable part 18 is tightly connected to the rigid part 13, e. g., by pasting.

To enable the low-cost manufacture of part 18, it is preferably made from a low-cost synthetic thermoplastic. In this case part 18 can be injection-molded. However, a plastic must be selected which has several partly contradictory properties: The plastic should be sufficiently (i. e., very pronouncedly) vaportight to preclude the drying of ink as far as possible; otherwise the advantage of the enlarged ink reservoir would be offset partially by a thickening of the ink as a result of evaporation, involving a loss of writing fluid and being a disadvantage also because the viscosity of the ink should not exceed a certain value. Obviously the plastic selected should resist the attack of ink. It has been found that a material very well complying with these requirements is a highpolymer polyethylene sold by Imperial Chemical Industries Limited under the name Alkathene Of this material the grades having a molecular weight between 17,000 and 20,000 have proved particularly satisfactory. For the manufacture of part 18 the grades Alkathene 2 and Alkathene 7 have given good results, whereas hard Alkathenes are preferable for parts not requiring appreciable elastic deformation.

To fill a fountain pen designed according to Fig. l and having a reservoir part 16 of elastically deformable material first the cap 14 has to be removed by unscrewing same from part 13. Then tube 15 is dipped into the ink bottle and the cylinder 13 is compressed laterally. Thereby part of the air enclosed in the space 16 is forced outwardly through the riser tube 15 and the ink in the supply bottle provided that there exists a communication between the tube 15 and the reservoir 16. When subsequently released the part 18 will reassume its original shape, the volume 16 being enlarged and, provided that the end of the tube 15 still extends below the ink level in the supply vessel, the ink will be sucked through the tube 15 and, emerging through the upper end of the tube 15 will flow down and collect in the lower part of the chamber 16.

To preclude the possibility that undue compression of the reservoir when lifted out of the ink supply would result in the reduction of the volume of the reservoir to raise the level of ink above the opening of riser tube 15, the riser tube is to be formed so as to close automatically as the casing is removed from the ink bottle. This is accomplished suitably in that the riser tube or part thereof is displaceable relative to a stationary sealing part against the action of an additional spring, which tends to displace the tube outwardly by a predetermined length into a position in which the flow of ink into the reservoir is prevented because a passage has been closed. Only when the tube has been displaced toward the interior of the pen casing by pressing the tube end projecting out of the casing against the bottom of the ink bottle or another stop provided within the ink container out of which the pen is to be refilled, the tube is moved into the position permitting a flow of ink and lling of the pen.

Fig. l of the drawing schematically illustrates this feature of the invention. The tube 15 is axially slidable though tightly guided in the valve part 5. To this end the part 5 is long enough to find safe guidance at the tube 15. A spring 40 tends to move the tube 15 outwardly by means of a flange 41 nondisplaceably provided at the latter. This displacement is limited by another flange 4Z bearing on the part 22, provided the cap 14 has been removed. With the cap 14 in the position shown there remains some clearance between the parts 42 and 22. The tube 15 has a transverse opening 43, which is covered by the body 5 when the tube is in the position shown in the drawing. The opening 43 can be moved into register with the opening 17 by a displacement of the tube against the action of the spring 4t). The spring 4@ is much weaker than the valve spring 11 so that axial pressure exercised on the tube 15 in the direction towards the nib 1 will move the tube 15 first against the valve body 4 until the face 44 engages the bottom 45, before the valve can be opened by continued pressure on the tube 15, when the cap 4 is removed, the riser tube 15 is moved by the spring 49 automatically into a position in which the flange 42 abuts against the part 22. In this position the transverse bore 17 of the valve body 4 is closed by a wall part of the tube 15. Since the riser tube 15 is guided tightly both in the valve body 4 and in the guide part 22, no liquid can enter the tube 15 out of the interior of the container 18 when the latter is compressed, provided that the parts 15 and 5 are in a relative position as shown in the drawing.

When the cap 14 has been removed and the tube 15 has been moved outwardly by the spring 40 so that the flange 42 engages with the end face of the guide part 22 the communication between the tube 15 and the reservoir 16 is interrupted. To fill the pen, it is introduced with its rear end into the ink bottle the nib pointing upwardly and is depressed against the bottom thereof or another stop in the bottle until the end 44 of the tube 15 meets bottom 45. This is felt distinctly owing to the considerable strain of the spring 11. in this position the lateral opening 43 of the riser tube communicates with the lateral outlet passage 17 of the valve body so that in this position of the riser tube the reservoir can be filled by repeatedly compressing and releasing the reservoir body 18. When the pen is removed from the ink bottle the tube 15 is moved back into a position as shown in the drawing, in which the ink reservoir 16 is closed to the outside. As the closing cap is screwed on the riser tube 15 is be moved inwardly until the tube end 44 is just in front of the bottom 45 of the aperture 17, but does not bear thereon. The spring 46 can be effective in the sense of an outward displacement of the tube 15 only when the cap 14 has been removed.

To avoid the presence of several detached parts in filling the pen shown the protective outer sleeve 14, the sealing cap 23 and the intermediate parts holding the latter, as well as the push button 24 form a unil as follows:

By means of a fiange 32 the part 28 spaces and partly connects parts 23 and 14. The push button 24 has a fiange 33, which is embraced by a rim 34 of the protective outer sleeve 14 without restricting the freedom of movement of part 24 relative to the inside of the sleeve 14. Hence, to assemble the sleeve part, the push button 24 is first introduced into the sleeve 14. The button 24 is prevented from falling out of the sleeve 14 by its flange 33 and the rim 34. Then the spring 25 and thereafter the support ring 26 and the spring 27 with the sealing cap 23 carried thereby are inserted. Thereafter the parts movable in part 14 are secured against falling out by the snap ring 30, which is fixed in the cap 14. Screwing the cap 14 on the thread 31 thus has the following effects:

First the sealing member 23 consisting of soft rubber comes to bear on the end of the ink container 18; this end is stiffened by part 22. The bottom of the cap 23 at the' same time closes the end of the riser tube 15, perhaps with a particularly soft gasket interposed. The elasticity and yieldability of the cap 23 compensate for length inaccuracies which may exist between the sealing face of the cap 23 and the tube end. As the cap 23 is screwed on further, the parts 28 and 26 travel rearwardly thereby compressing the springs 27 and 25 respectively, until at last the ring 28 meets the shoulder 36 of the sleeve 14. Now the flange 32 is capable of transmitting the pressure required for a reliable seal. This sealing pressure is applied by the screw thread.

To open the antechamber valve 4 in order to fill the antechamber 7, it is sufficient to depress the push button 24, which now compresses the spring 25 and applies itself to the bottom of the cap 23. This bottom moves the tube 15 and with it the valve 4, in the direction toward the nib 1. This displacement of the bottom of the cap 23 is effected without involving a displacement of the surface 36 so that only the cylindrical part of the cap 23 is deformed. To enable this deformation, which involves a peripheral widening of the just mentioned portion of the cap 28, sufficient lateral clearance must be provided between the cap 28 on the one hand and parts 26 and 25 on the other.

The complete fountain pen comprises the usual protective cap fitting over the nib 1. This cap is not shown in the drawings because it is no subject of the invention and may be of known type. This protective cap may be provided with an internal screw thread and in this case is screwed on the external. thread 37. A1-

ternatively the screw cap may be replaced by a cap held on the casing part by friction; this type of cap is also known per se.

It is apparent that the embodiment described hereinbefore permits of numerous variations and for this reason is not to be construed as limiting. This invention comprises also these variations if they are within the scope of the appended claim.

We claim:

In a fountain pen, in combination, a casing forming an antechamber, said casing being provided with a deformable wall portion defining an ink reservoir connected by a passage to said antechamber, a nib mounted at the front end of said casing for communication with said antechamber, valve means in said passage normally isolating said ink reservoir from said antechamber, a riser tube mounted in said casing for relative axial displacement and operatively connected with said valve means, said riser tube forming a channel between said ink reservoir and the rear end of said casing for the filling of said ink reservoir from said rear end, operating means at the rear end for temporarily opening the passage by actuating the valve means through axial displacement of the riser tube, said valve means further constituting stationary channel means matingly engaging part of said riser tube, said channel means and said riser tube being provided with respective openings aligned in a first position of said riser tube and disaligned in a second position of the latter, the opening of said channel means communicating with said ink reservoir, removable cap means on the rear end of said casing, said riser tube having a rear extremity projecting from said casing upon removal of said cap means, and means urging said riser tube into said second position thereof, pressure upon said projecting extremity displacing said riser tube into said first position, thereby establishing a connection between said riser tube and said ink reservoir for the filling of the latter.

References Cited in the file of this patent UNITED STATES PATENTS 1,864,050 Myers June 21, 1932 2,425,143 Brubaker Aug. 5, 1947 2,567,618 Quaintance Sept. 11, 1951 2,603,188 McKay July 15, 1952 FOREIGN PATENTS 6,570 Great Britain 1915 818,824 France June 28, 1937 472,383 Great Britain Sept. 22, 1947 983,759 France Feb. 14, 1951 

